Alkylaluminoxane, e.g., methylaluminoxane, is made by the reaction of a trialkylaluminum, e.g., trimethylaluminum, with water in an organic solvent medium which is inert to the reaction. Since the reaction between water and a trialkylaluminum compound, particularly trimethylaluminum, is highly exothermic and quite difficult to control, investigators have used a wide variety of differing techniques to achieve a controllable reaction of these reagents in order to synthesize the desired alkylaluminoxane which is useful as a co-catalyst for olefin polymerization reactions with certain metallocene components, e.g., certain Group IVB compounds such as dicyclopentadienylzirconium dichloride. Some U.S. Pat. Nos. which are considered germane to this area of technology and which illustrate various specific techniques that have been used to combine liquid water and a trialkylaluminum reagent in aluminoxane synthesis are the following: U.S. Pat. Nos. 3,300,458; 4,730,071; 4,730,072; 4,772,736; 4,908,463; 4,924,018; 4,937,363; and 4,968,827.
U.S. Pat. No. 4,960,878 describes the synthesis of "modified" methylaluminoxane materials using various process embodiments. One embodiment, i.e., the third enumerated embodiment, involves the initial synthesis of a polyalkylaluminoxane containing C.sub.2 or higher hydrocarbyl (e.g., alkyl) groups with the subsequent reaction of this polyalkylaluminoxane with trimethylaluminum and then with water. The trimethylaluminum is said in that patent to complex with the polyalkylaluminoxane prior to subsequent reaction with water (Col. 3, lines 49-52).
Recent U.S. Pat. No. 5,003,095 relates to the reaction of a methyl halide using a bismuth-containing catalyst with an alkylaluminoxane having two or more carbons via alkyl group exchange to form methylaluminoxane.
One very efficient way in which liquid water and trialkylaluminoxane can be combined in an alkylaluminoxane synthesis procedure is described in copending U.S. patent application Ser. No. 534,913, filed Jun. 8, 1990 in which atomized liquid water in the form of a spray, mist, or fog and the selected trialkylaluminum compound are combined in an organic solvent of the type used in conventional synthesis procedures for alkylaluminoxane synthesis.